The present invention relates generally to apparatus for handling articles such as can ends or the like. More particularly, the invention concerns a novel and improved control apparatus for use with an article handling system for controlling or regulating the flow of articles in a desired fashion at various points in the system.
While the invention may find application in other article handling situations, the description will be facilitated hereinafter by specific reference to the problem of handling and processing can ends. The manufacture and handling of can ends has become a highly automated process, employing high speed manufacturing and handling apparatus and requiring rapid transfer of the articles or can ends from one work station to another. The manufacturing operation may include a number of machines which perform various fabrication, counting, and packaging steps on the can ends. Generally speaking, the can ends are carried in elongate conduits in a facewise nested condition between one work station in the system and the next.
The apparatus of the invention may also find use in can end handling operations attendant to the final end user. For example, the invention may be used with apparatus which accumulates a large number of stacks or sticks of can ends of a predetermined length or number and discharges these sticks of can ends as required into an infeed for a filling or canning operation. Such operations may at some points utilize various gases for sterilization and/or isolation of the product filling process from other components. For example, some liquid products are filled in a nitrogen atmosphere to substantially limit or eliminate oxygen inside of the can or other container. As will be more fully explained hereinbelow, the apparatus of the invention may advantageously be utilized as a gas seal unit in can end conduits feeding such a filling apparatus.
In addition to the foregoing gas seal application, the control apparatus of the invention may be used in a number of other applications wherein it is desired to control the flow of articles between one work station or location and the next. For example, in some applications it is desired to provide a so-called air gap or control gap at some point in the conduit. When the can ends or other articles back up in the conduit and fill this control gap or conversely, should the articles advance completely out of the air gap or control gap, a signal may be provided to indicate that the supply of articles at the control gap does not match the demand for articles downstream. One such air gap control system is shown for example in prior U.S. Pat. No. 3,618,550 which is commonly owned herewith.
In yet other applications, a relatively long, generally vertical column of articles or can ends may travel through a section of a conduit or be introduced into a conduit at some point in the system. In such instances, it may be desired to control the overall weight or pressure applied by such an elongated vertical column of articles or can ends. In a similar application, a relatively elongate vertical column of can ends is to be released from a rotary accumulator unit into a conduit upon receipt of a signal indicating a downstream demand for the articles or can ends. In this instance, it is desired to provide some further control of the velocity or speed of release of the articles from the elongate vertical column of articles into the receiving conduit. In particular, this latter application occurs in the case of the discharge end of a carousel-type rotary end feeder or accumulator unit of the type described for example in U.S. Pat. No. 3,722,741 which is commonly owned herewith.